1. Field of the Invention
The present invention relates to a device monitoring technique that acquires management information from a device connected to a network.
2. Description of the Related Art
In a printer management system that manages a printer connected to a network, the management such as printer maintenance and accounting is performed based on specific management information. The management information may include information on the printer such as the total printed sheet count, trouble information, the print job count, and usage of consumable supply (for example, paper and toner) for each print job. To acquire this kind of management information, a printer monitoring apparatus for monitoring the printer is connected to the network.
Acquisition of the management information with the printer monitoring apparatus, in many cases, is performed with Simple Network Management Protocol (SNMP). Specifically, to acquire the management information with SNMP, the printer monitoring apparatus sends to the printer a request message requiring the management information, and the printer sends to the printer monitoring apparatus a response message in response to the request message.
However, with SNMP, the destination of the sending and receiving message is identified by an IP address, so a problem may arise under environments in which the IP address may change. For example, when printer management is performed with the NetBIOS protocol, since the printer is specified using a NetBIOS name, the printer IP address may be set dynamically using Dynamic Host Configuration Protocol (DHCP). Also, a fixed IP address of a printer may be changed with relocation of the printer. In these cases, there is the risk that the printer monitoring apparatus is not able to send SNMP messages to the printer subject to monitoring, and to acquire the management information. This problem is common not only to cases when the printer is identified by an IP address, but also generally in cases when the information for identifying the printer may change. This problem is also common not only to a printer monitoring apparatus that acquires printer management information, but also to other device monitoring apparatus that acquires management information of individual device connected to a network.